GENDER BIAS IN MAMMALIAN DNA REPLICATION DURING DEVELOPMENT

发育过程中哺乳动物 DNA 复制的性别偏见

• 批准号: 9407791
• 负责人: John C Schimenti
• 金额: $ 31.33万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-05 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9407791
• 关键词: Ablation; Address; Alleles; Androgen Receptor; Animals; Anti-inflammatory; Basic Science; Biological Process; Birth; Cells; Cessation of life; Characteristics; Chemicals; Cultured Cells; DNA Biochemistry; DNA Damage; DNA biosynthesis; Data; Defect; Development; Disease; Embryo; Embryo Transfer; Embryonic Development; Environment; Event; Female; Fibroblasts; Fostering; Gender; Genes; Genetic; Genomic Instability; Genotype; Glucocorticoids; Goals; Heterozygote; Human; Hypersensitivity; Ibuprofen; Inflammation; Inflammatory; Inflammatory Response; Inherited; Interleukin-10; Interleukin-6; Intervention; Lead; Licensing; MCM2 gene; Maintenance; Malignant Neoplasms; Mammals; Measures; Mediating; Molecular Analysis; Mothers; Mus; Non-Steroidal Anti-Inflammatory Agents; Organism; Outcome; Partner in relationship; Pathway interactions; Pregnancy; Process; Proteins; Replication Licensing; Replication Origin; Research; Risk; Secondary to; Sex Bias; Spontaneous abortion; Stress; Testing; Testosterone; Tissues; Transgenes; X Inactivation; adverse pregnancy outcome; cytokine; experimental study; fetal; gender difference; helicase; inflammatory marker; male; mutant; novel; pregnant; prevent; response; risk variant; senescence; sex; sex determination; sexual dimorphism; zygote

Project Abstract DNA replication is the most essential event in the propagation of a species. Defects in this process can cause diseases including birth (developmental) defects and cancer. When DNA replication is compromised genetically or environmentally, a state known as “replication stress” (RESS) occurs that can lead to the aforementioned deleterious outcomes. Extensive basic research on the biochemistry of DNA replication has been conducted in single celled organisms and cultured cells, without regard for potential gender differences that may exist in higher organisms such as mammals. The goal of this project is to understand how the universal process of DNA replication is subject to dramatic sexual dimorphism in mammalian embryogenesis. Preliminary studies found that female mouse embryos were dramatically more prone to lethality when levels of the MCM2-7 (Minichromosome maintenance 2,3,4,5,6,7) DNA replication licensing and helicase proteins were genetically reduced and the helicase destabilized. Subsequent studies revealed that the female-biased lethality began occurring immediately after sex determination, and was not related to defects in X-inactivation.Transgene-mediated conversion of female embryos to males or testosterone administration reversed the gender-biased lethality, indicating that the phenomenon is related to secondary sexual characteristics. Further experiments suggested that testosterone enabled female embryo rescue by virtue of its anti-inflammatory activity, a possibility supported by the observation that ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), also rescued MCM-deficient female embryos. This project seeks to elucidate the cellular and mechanistic basis of this novel example of mammalian sexual dimorphism. Aim 1 will test whether female- biased embryo lethality in MCM-depleted animals is due to gender differences in DNA replication per se, or differential sensitivity to intrinsic RESS. Aim 2 will test the hypothesis that female embryo hypersensitivity is related to RESS-induced inflammation, while males embryos are protected by the anti-inflammatory activity of testosterone they produce in high levels following sex determination. Aim 3 will explore the basis of preliminary data showing that a key contributing factor in the sex bias phenomenon is the maternal environment; only dams with intrinsic RESS preferentially lost female embryos. This will be accomplished transferring at-risk genotypes of zygotes into foster mothers that are genotypically wild-type, MCM-deficient, or deficient for the anti-inflammatory cytokine IL-10. Overall, these studies will can impact our understanding of the relationships between RESS, inflammation, and adverse pregnancy outcomes related to maternal and/or fetal inflammatory responses that are genetically or environmentally induced.

项目摘要 DNA复制是物种繁殖中最重要的事件。此过程中的缺陷可能 导致疾病，包括出生（发育）缺陷和癌症。当DNA复制时 当基因或环境受到损害时，会出现一种称为“复制应激”(RESS) 的状态 可能导致上述有害结果。广泛的生物化学基础研究 DNA复制已在单细胞生物和培养细胞中进行，不考虑 高等生物（如哺乳动物）中可能存在潜在的性别差异。此举的目标 该项目旨在了解 DNA 复制的普遍过程如何受到戏剧性的性影响 哺乳动物胚胎发生中的二态性。初步研究发现，雌性小鼠胚胎 当 MCM2-7（微型染色体维护 2,3,4,5,6,7) DNA复制许可和解旋酶蛋白被基因减少并且解旋酶 不稳定。随后的研究表明，女性偏向的致死率立即开始发生 性别决定后，与 X 失活缺陷无关。转基因介导的转化 将女性胚胎移植为男性或注射睾酮逆转了性别偏见的致死率， 表明该现象与第二性征有关。进一步的实验 表明睾酮凭借其抗炎活性能够挽救女性胚胎， 观察结果支持了这种可能性，即布洛芬，一种非甾体抗炎药（NSAID）， 还拯救了 MCM 缺陷的雌性胚胎。该项目旨在阐明细胞和 这个哺乳动物两性异形的新例子的机制基础。目标 1 将测试是否 MCM 耗尽的动物中雌性偏向的胚胎致死率是由于 DNA 的性别差异造成的 复制本身，或对内在 RESS 的不同敏感性。目标 2 将检验以下假设：女性 胚胎过敏与RESS诱导的炎症有关，而雄性胚胎受到保护 通过睾酮的抗炎活性，它们在性别决定后产生高水平的睾酮。 目标 3 将探索初步数据的基础，这些数据表明性别偏见的一个关键影响因素 现象是母体环境；只有具有内在RESS的母坝优先失去雌性 胚胎。这将通过将受精卵的高危基因型转移到养母体内来实现 基因型为野生型、MCM 缺陷或抗炎细胞因子 IL-10 缺陷。全面的， 这些研究将影响我们对 RESS、炎症和疾病之间关系的理解 与母体和/或胎儿炎症反应相关的不良妊娠结局 遗传或环境引起的。